<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
  <meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no, width=device-width">
</head>
<body>
	<button type="button">CLEAR!!!!!!!!!!!!!!!!!!!</button>
	<script type="text/javascript">
	function clear() {
		localStorage.clear();
		alert('Yeah!!!!!!!!!!!');
	}
	document.querySelector('button').addEventListener('click', clear, false);
	</script>
</body>
</html>